Researchers at the University of Rochester have recently made significant strides in quantum technology, specifically in the realm of creating and manipulating excitons within two-dimensional (2D) materials. By taking two flakes of special materials that are only one atom thick and twisting them at high angles, they have discovered unique optical properties that have the potential to revolutionize quantum computing and other quantum technologies. This groundbreaking research is documented in a new study published in the prestigious journal Nano Letters, highlighting how the precise layering of nano-thin materials can create artificial atoms, or excitons, that could serve as quantum information bits, known colloquially as qubits.
The focus of this research is molybdenum diselenide, a 2D material that exhibits distinctive quantum characteristics when manipulated correctly. Previous studies have primarily centered on graphene, a well-known 2D material that has garnered attention for its quantum properties. However, the team from Rochester’s Institute of Optics and Department of Physics and Astronomy has taken an unconventional approach, utilizing larger twisting angles of up to 40 degrees. This is a stark contrast to the "magic" angle of 1.1 degrees associated with graphene, which has been the subject of much focus in the field of quantum materials.
One of the striking revelations from this research is that the twisted monolayers of molybdenum diselenide still produced excitons capable of retaining information when exposed to light. Researchers were surprised by this outcome, considering that molybdenum diselenide has historically been considered a more fickle material compared to its graphene counterparts. Despite this unpredictability, their findings suggest that utilizing other materials from the same family at large angles could yield even better results. The implications of this discovery are profound, as the ability to manipulate these excitons could lead to advancements in quantum devices.
The study illuminates a deeper understanding of excitons, which are bound states of electrons and holes in a semiconductor. These excitons, formed in the twisted layers of molybdenum diselenide, can act as artificial atoms due to their unique properties. The researchers, led by Nickolas Vamivakas, the Marie C. Wilson and Joseph C. Wilson Professor of Optical Physics, emphasize that these dark excitons, which typically do not interact with light in a single layer, can be optically controlled when in layered configurations that include twists. This foundational understanding of exciton behavior is critical in developing future quantum devices, particularly those aimed at information retention and transfer within quantum networks.
The researchers draw a parallel between their work and the 2010 Nobel Prize-winning discovery related to graphene. This pivotal moment in science demonstrated that peeling carbon down to a single layer creates a novel 2D material with unique quantum traits. The Rochester team has built upon this foundational knowledge, pushing the boundaries further by exploring how different 2D materials can achieve similar results, even when their properties are not as stable as graphene’s.
As the researchers delve deeper into the optical and electrical behavior of these materials, they aim to explore new possibilities for creating more efficient quantum devices. The potential applications of these advancements go beyond the laboratory. Vamivakas and his team envision a future where these artificial atoms could be essential components in developing memory storage systems or nodes in extensive quantum networks. Such capabilities could revolutionize technologies such as next-generation lasers and even tools designed to simulate intricate quantum phenomena.
An essential aspect of this research involves the collaboration and support from the Air Force Office of Scientific Research, which has provided necessary funding for these investigations. Conducted at the URnano facilities, the work showcases the ongoing commitment to advancing the field of quantum technology. The researchers’ efforts underscore the importance of understanding the fundamental aspects of quantum materials that can significantly impact various industries and applications in the future.
In summary, the work completed by the University of Rochester team represents a crucial early step toward realizing practical applications of quantum phenomena in technology. As they continue exploring the possibilities of twisted monolayers and artificial atoms, the implications for future quantum devices become increasingly promising. This research exemplifies how innovative approaches can unlock new pathways in established scientific realms, paving the way for advancements that may soon transform our understanding and utilization of quantum systems.
The convergence of optical properties and quantum information science presented in this study offers exciting prospects not only for academic research but also for practical implementations in technology. As we stand on the brink of the quantum revolution, the manipulation of excitons and the creation of robust qubits through novel 2D materials signal a new era in the quest to harness the power of quantum mechanics.
The insights gained from this research are set to inspire further exploration in the field, potentially leading to breakthroughs that could redefine how we approach quantum computation and information processing. With the scalability of these techniques, the pathway to mainstreaming quantum technologies is slowly being laid.
Ultimately, the advances made in this area represent not only a triumph for the scientists involved but also a beacon of hope for the future of technology that integrates the principles of quantum physics with everyday applications.
Subject of Research: The manipulation of excitons in two-dimensional materials for quantum technologies.
Article Title: Diffusion of Valley-Coherent Dark Excitons in a Large-Angle Incommensurate Moiré Homobilayer
News Publication Date: 14-Mar-2025
Web References: University of Rochester, Nano Letters
References: 2010 Nobel Prize in Physics, URnano facilities
Image Credits: University of Rochester photo / J. Adam Fenster
Keywords Quantum information science, Qubits, Excitons, Optical properties, Superlattices, Quantum computing, Laser systems.
